1. Field of the Invention
This invention relates to a novel use of a fat emulsion containing a compound having prostaglandin E.sub.1 activity. More particularly, it relates to an angiographic adjuvant, or an adjuvant used for promoting the blood flow in a region where angiography is to be performed, so as to make clear the angiographic pictures.
2. Related Art
Angiography is a clinical technique for observing the flow of a contrast medium such as an iodine compound injected into a blood vessel in a region by taking the pictures of such a flow of contrast medium through the vascular system in the region by X-ray photography, X-ray filming or other means. Angiography is used for diagnostical purposes such as (1) diagnosis on expansion or state of lesion in a blood vessel itself, (2) diagnosis of lesion, or its expansion, in various internal organs and their peripheral tissues from exclusive shadow or infiltrative shadow of the blood vessel, and (3) diagnosis on vascular movement or function by continuous photographing of the flow of contrast medium. For example, contrasting of superior mesenteric arteries is an important contrasting examination which is widely used for making decision on practicing arterial embolectomy for primary liver cancer, determination of the scope of infiltration of pancreatic cancer, diagnosis on esophageal varices, etc.
Hitherto, vasodilators such as prostaglandin E.sub.1 (hereinafter referred to as PGE.sub.1) injection and nitroglycerin injection have been used as angiographic adjuvant for making clear the pictures appearing on the screen or the photographs taken by angiography by increasing the blood flow in the region being examined when performing angiography.
The conventional angiographic adjuvants, however, were short in tolerable duration of sustained administration, making it hard to maintain their efficacy for a long time. It was also necessary to administer them at a high dose for performing long-time angiographical observation or for preventing embolus of fine blood vessels after angiography. Further, administration of said conventional adjuvants is accompanied with certain adverse side effects. For instance, it is reported that PGE.sub.1 injection into superior mesenteric arteries may cause abnormal abdominal symptoms such as abdominal pain, burning sensation, tractional sensation, etc., and variation of blood pressure.
For eliminating these problems, an angiographic adjuvant capable of long-time retention in the system and showing a satisfactory efficacy at a small dose has been desired.